1. Field
Embodiments of the invention relate to the field of camera lenses; and more specifically, to lens mounts for securing an additional lens in the photographic light path.
2. Background
Cameras are being added to multi-function devices such as computers and mobile telephones that do not provide the structures found in conventional cameras that provide only an image capture function. Multi-function devices are often thin, offering little room for the optical elements of the camera portion of the device. This has led to the development of extremely compact camera modules that provide increasingly sophisticated image capturing in a very small device. In turn, the availability of these small camera modules has resulted in the production of extremely compact and thin single function cameras that also lack the structures found in conventional cameras.
Regardless of the amount of miniaturization of these camera modules, there is a limit to the types of optics that can be provided in the space available in a multi-function device or ultra-compact camera. The optics for providing a telephoto lens and other specialty lenses require a certain length for their optical path, which often is unavailable within a small device. Further, users generally want to use a specialty lens intermittently. Therefore it is desirable to be able to change the lenses that are in the optical path to provide specialty optics when desired.
It is possible to provide an additional lens, which may be an assembly including multiple lens elements, that works in conjunction with a lens provided by a camera module to provide specialty lens functions. When an additional lens is placed in the photographic light path, it is important that the additional lens be aligned with the optical axis of the lens provided by a camera module to provide good image quality. Existing compact devices that use compact camera modules generally do not provide the types of lens mounting structures found in conventional cameras due to space constraints. This makes it difficult to retain an additional lens and align it correctly with a compact camera module on a compact device.
It would be desirable to provide a lens mount for an additional lens that works in conjunction with a lens provided by a camera module on a compact device.